Thailand has long had a reputation as one of the most idyllic places on earth. But the recent murder of a British backpacker has put its previously unseen dangers into the spotlight

When Katie Gill decided to visit Koh Samui during her round-the- world trip she had an image in her mind of the most pleasurable place on the planet. Kilometers of white sandy beaches, clear azure water sparkling in the sunlight, cheap beachfront accommodation, serenity, solitude and, above it all, a crown of coconut palms blowing in the breeze. Like many things in life, it didn't quite live up to the fantasy. She didn't, for instance, expect to see a Starbucks or McDonald's. And it was much busier and noisier than she'd expected.

But she wasn't too disappointed. When she sat on the sand listening to the waves splashing gently on the shore, it felt as close as she would ever get to that funny old concept called paradise.

Katie had planned on staying a few days, but after a week decided to abandon the rest of her adventure around the globe and stay for ever on the small island on the Gulf of Thailand.

On a hot and sticky evening last week, some two years after she arrived, the 25-year-old from Derbyshire, England, sat outside one of the few remaining bars in the town of Lamai that she still feels safe in, sipping an ice-cold Singha beer.

The pot-holed and flood-damaged road through the town was teeming with traffic, the air thick with dust and petrol fumes. Stalls offering lethal local whisky and fake designer goods competed for pavement space with stray dogs and people selling chickens and ducks. On the narrow road, hundreds of motorcycles tried to out-do each other by constantly blasting their horns, while dilapidated jeeps crawled along, their Tannoys blaring adverts for the best foam parties.

In the glut of neon-lit "lady bars," drunken, lonely Western men were propped up by groups of beautiful Thai women, giggling and whispering and wondering whether tonight was going to be the night that they would get lucky and hit on a man with a bulging wallet and an urge to get married. Were they shocked by the news, with the men already caught, of the rape and murder of the Welsh student Katherine Horton? Yes, it seems. But they may well be the only ones.

"It's not paradise any more and I guess it never will be," said Katie, surveying the scene around her. "For the first time since I came here I don't feel safe. I used to live on the beach and would often walk alone to bars or wander home a little bit drunk on my own.

"I never felt scared. I used to think in a place like Koh Samui, as a single female, nothing could go wrong. I actually thought it was more dangerous for single foreign guys because they are always getting ripped off by bar girls and lady boys. Now I would be afraid to walk along the beach on my own and I rarely socialize. For the first time in two years I have actually been longing for home."

She is not the only one. Since the murder on New Year's Day, many British tourists have abandoned the tropical resort, unable or unwilling to accept that the worst horrors of the modern world can also reside in a place they thought was the nearest thing to heaven on earth.

Last week, two illiterate and impoverished fishermen, who pleaded guilty to rape and murder, were sentenced to death for the crime.

As they awaited the judge's ruling, a new picture of Thailand was emerging, a sharp contrast to the palm trees of the brochures. Spiralling violence and corruption on the island is growing amid increasing resentment among some Thais about its unregulated over-development. I have also spoken to British women who claim Thai police do not treat rape seriously.